This study describes the preparation and characterization of nanocomposites obtained by melt-mixing of poly (ethylene-co-vinyl acetate) (EVA), polylactic acid (PLA), and TiO2 nanoparticles (TNPs) via three different methods of direct mixing, one-step, and two-step methods. Vinyltrimethoxysilane was used as a surface modifier for the TNPs. The one-step method showed the best suitability for the preparation of EVA/PLA/TiO2 nanocomposites. The increase in torque and the adhesion of the TNPs with EVA/PLA matrix in these nanocomposites showed enhanced interfacial interactions between EVA, PLA chains, and TNPs. The tensile strength, Young's modulus, dynamic storage modulus, and thermooxidative stability of the one-step prepared nanocomposites were higher than those of two other nanocomposites and that of the EVA/PLA blend, reaching maximum values at 2.0 wt% of TNPs.

Keywords: nanocomposites; polylactic acid; poly(ethylene-co-vinyl acetate); mixing; blend